Two-dimensional tr probe array

ABSTRACT

An ultrasonic sensor assembly includes a flexible supporting material that has flexibility configured for allowing bending of the supporting material to conform to a cylindrical shape of a pipe. The assembly includes a plurality of operable sensor elements arranged in a matrix formation upon the flexible supporting material. The matrix formation includes a plurality of rows of the sensor elements and a plurality of columns of the sensor elements. The flexible supporting material is configured for placement of the columns of the matrix formation to extend along the elongation of the pipe and the flexible supporting material is configured for placement of the rows of the matrix formation to extend transverse to the elongation of the pipe. The flexible support material is configured to flex for positioning the sensor elements within each row in a respective arc that follows a curve of the cylinder shape of the pipe.

RELATED APPLICATION

Benefit of priority is hereby claimed from U.S. patent application Ser.No. 13/680,183, filed Nov. 19, 2012, entitled TWO-DIMENSIONAL TR PROBEARRAY, the entire disclosure of which is hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to ultrasonic sensor assemblies,and more particularly, to an ultrasonic sensor assembly including asensor array of sensor elements.

2. Discussion of the Prior Art

Ultrasonic sensor assemblies are known and used in many differentapplications. Ultrasonic sensor assemblies are used, for example, toinspect a test object and detect/identify characteristics of the testobject, such as corrosion, voids, inclusions, length, thickness, etc. Inpipeline corrosion monitoring applications, the test object typicallyincludes a metallic pipe. In such an example, a transmitter-receiver(“TR”) probe is provided for detecting/identifying the characteristicsof the pipe. However a single TR probe occupies a relatively small areaand, thus, has a relatively small testing range. Also, the pipe may havean arcuate contour surface. Detecting characteristics of the entire pipewith one TR probe can be inaccurate and time consuming. Accordingly, itwould be beneficial to provide an ultrasonic sensor assembly that canaddress such issues. Further, it would be beneficial to provide thissensor array with a contoured shape that matches the shape of the testobject.

BRIEF DESCRIPTION OF THE INVENTION

The following presents a simplified summary of the invention in order toprovide a basic understanding of some example aspects of the invention.This summary is not an extensive overview of the invention. Moreover,this summary is not intended to identify critical elements of theinvention nor delineate the scope of the invention. The sole purpose ofthe summary is to present some concepts of the invention in simplifiedform as a prelude to the more detailed description that is presentedlater.

In accordance with one aspect, the present invention provides anultrasonic sensor assembly for testing a tubular pipe that has acylindrical shape and has an elongation along the extent of the pipe.The ultrasonic sensor assembly includes a flexible supporting materialthat has flexibility configured for allowing bending of the supportingmaterial to conform to the cylindrical shape of the pipe. The ultrasonicsensor assembly includes a plurality of operable sensor elementsarranged in a matrix formation upon the flexible supporting material.The matrix formation includes a plurality of rows of the sensor elementsand a plurality of columns of the sensor elements. The flexiblesupporting material is configured for placement of the columns of thematrix formation to extend along the elongation of the pipe and theflexible supporting material is configured for placement of the rows ofthe matrix formation to extend transverse to the elongation of the pipe.The flexible support material is configured to flex for positioning thesensor elements within each row in a respective arc that follows a curveof the cylinder shape of the pipe.

In accordance with another aspect, the present invention provides amethod for testing a tubular pipe that has a cylindrical shape and thathas an elongation along the extent of the pipe using an ultrasonicsensor assembly. The method includes providing the ultrasonic sensorassembly. The assembly includes a flexible supporting material that hasflexibility configured for allowing bending of the supporting materialto conform to the cylindrical shape of the pipe. The assembly includes aplurality of operable sensor elements arranged in a matrix formationupon the flexible supporting material. The matrix formation includes aplurality of rows of the sensor elements and a plurality of columns ofthe sensor elements. The flexible supporting material is configured forplacement of the columns of the matrix formation to extend along theelongation of the pipe and the flexible supporting material isconfigured for placement of the rows of the matrix formation to extendtransverse to the elongation of the pipe. The flexible support materialis configured to flex for positioning the sensor elements within eachrow in a respective arc that follows a curve of the cylinder shape ofthe pipe. The method includes placing the ultrasonic sensor assemblyonto the pipe. The step of placing the assembly includes engaging theflexible supporting material to the pipe to place the columns of thematrix formation extending along the elongation of the pipe and the rowsof the matrix formation extending transverse to the elongation of thepipe. The step of placing the assembly includes bending the flexiblesupport material for positioning the sensor elements within each row ina respective arc that follows a curve of the cylinder shape of the pipe.The method includes operating the sensor elements.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of the present invention will becomeapparent to those skilled in the art to which the present inventionrelates upon reading the following description with reference to theaccompanying drawings, in which:

FIG. 1 is a schematic, perspective view of an example ultrasound sensorassembly being used a test object in accordance with an aspect of thepresent invention;

FIG. 2 is a schematic view of an example sensor array of the ultrasoundsensor assembly;

FIG. 3 is a schematic view of one example sensor element for use in thesensor array of FIG. 2; and

FIG. 4 is a schematic, perspective view of the example sensor arraybeing moved with respect to the test object.

DETAILED DESCRIPTION OF THE INVENTION

Example embodiments that incorporate one or more aspects of the presentinvention are described and illustrated in the drawings. Theseillustrated examples are not intended to be a limitation on the presentinvention. For example, one or more aspects of the present invention canbe utilized in other embodiments and even other types of devices.Moreover, certain terminology is used herein for convenience only and isnot to be taken as a limitation on the present invention. Still further,in the drawings, the same reference numerals are employed fordesignating the same elements.

FIG. 1 illustrates a perspective view of an example ultrasonic sensorassembly 10 according to one aspect of the invention. In short summary,the ultrasonic sensor assembly 10 includes a controller 20 and a sensorarray 30 that can be positioned in proximity to a test object 12. Thesensor array 30 transmits ultrasonic waves into the test object 12 todetect characteristics of the test object 12. These characteristicsinclude corrosion (e.g., thickness and location of corrosion), wallthickness, voids, inclusions, etc. The sensor array 30 is operativelyattached to the controller 20 by means of a wire 22 (or may bewireless). To provide improved sensing of the test object 12, the sensorarray 30 includes a plurality of sensor elements arranged in a twodimensional array.

The test object 12 is shown to include a tubular pipe having a generallycylindrical shape extending between a first end 14 and an opposingsecond end 16. The test object 12 can include a non-solid body (e.g.,hollow body) or may be solid. It is to be appreciated that the testobject 12 is somewhat generically/schematically depicted in FIG. 1 forease of illustration. Indeed, the test object 12 is not limited to thepipe extending along a linear axis, and may include bends, undulations,curves, or the like. The test object 12 has an outer surface 18 forminga generally cylindrical shape. In other examples, the test object 12could include other non-cylindrical shapes and sizes. For example, thetest object 12 could have a non-circular cross-sectional shape, such asby having a square or rectangular cross-section. In other examples, thetest object 12 further includes a tubular shape, conical shape, or thelike. Even further, the test object is not limited to pipes, butinstead, could include walls, planar or non-planar surfaces, etc. Assuch, the test object 12 shown in FIG. 1 comprises only one possibleexample of the test object.

Turning to the controller 20, the controller is somewhatgenerically/schematically depicted. In general, the controller 20 caninclude any number of different configurations. In one example, thecontroller 20 is operatively attached to the sensor array 30 by means ofthe wire 22. As will be described in more detail below, the controller20 is configured to send and receive information (e.g., data, controlinstructions, etc.) from the sensor array 30 through the wire 22. Thisinformation can be related to characteristics of the test object 12. Forexample, in pipeline corrosion monitoring applications, the test object12 may be susceptible to imperfections, such as corrosion, cracks,voids, inclusions, or the like. As such, this information includes, butis not limited to, dimensions of the test object 12 (e.g., thickness,length, etc.), the presence or absence of corrosion for corrosionmapping, cracks, or the like. The controller 20 can include circuits,processors, running programs, memories, computers, power supplies,ultrasound contents, or the like. In further examples, the controller 20includes a user interface, display, and/or other devices for allowing auser to control the ultrasonic sensor assembly 10.

Focusing upon the operation of the sensor array 30, the sensor array 30is placed in proximity to the outer surface 18 of the test object 12and/or in contact with the outer surface 18. The ultrasonic sensorassembly 10 can include a single sensor array (as shown), or a pluralityof sensor arrays. The sensor array 30 is not limited to the positionshown in FIG. 1, as the sensor array 30 is moved along the outer surface18 of the test object 12. Indeed, the sensor array 30 could bepositioned at any number of locations along the test object 12, such ascloser towards a center, closer towards the first end 14 or second end16, etc. In one example, the sensor array 30 has a shape thatsubstantially matches a shape of the outer surface 18 of the test object12. For instance, as shown in FIG. 1, the sensor array 30 includes acurvature that substantially matches a curvature of the test object 12.The curvature could be larger or smaller in further examples, dependingon the size and shape of the test object 12. However, in other examples,the sensor array 30 need not have such a curvature, and may instead havea substantially planar shape.

Turning now to FIG. 2, the sensor array 30 will be described in moredetail. The sensor array 30 is not shown in proximity to the test object12 in FIG. 2 for illustrative purposes and to more clearly illustratethe elements of the sensor array 30. However, in operation, the sensorarray 30 is placed in proximity to the test object 12 as described withrespect to FIG. 1.

The sensor array 30 can include a supporting material 32 that providessupport to the sensor array 30. In one example, the supporting material32 is a resilient member having a predetermined shape. The supportingmaterial 32 can be non-flexible or, in other examples, could be providedwith some degree of flexibility or movement. As described above, thesupporting material 32 can include the curved shape that matches theshape of the outer surface 18 of the test object 12. However, thesupporting material 32 could also include the substantially planarshape. The supporting material 32 can include any number of materials,such as engineering plastics, polyimide materials, etc. In furtherexamples, the supporting material 32 could include a flexible orsemi-flexible member, allowing for the supporting material 32 to be bentor molded to a desired shape.

The sensor array 30 further includes one or more sensor elements 34 fordetecting characteristics of the test object 12. The sensor elements 34are somewhat generically depicted in FIG. 2, as the sensor elements 34include a number of different sizes, shapes, and configurations. Asshown in FIG. 2, the sensor elements 34 are arranged in a matrixformation. In the matrix formation, the sensor elements 34 may includeone or more rows 36 extending along a first direction (e.g a firstaxis). Within the shown example of FIG. 2, the first axis 38 extendsgenerally linearly along the sensor array 30. Of course, if the array 30has a curvature, the first direction can follow along such curvature.

The rows 36 each include a plurality of the sensor elements 34. In theshown example, the rows 36 each include eight sensor elements 34 (asshown) in a sequence, though the rows 36 could include as few as one ormore sensor elements or greater than eight sensor elements. The sensorelements 34 within each of the rows 36 are generally equidistant fromeach other, such that the sensor elements 34 are substantially equallyspaced from adjacent sensor elements along the length of the sensorarray 30. In further examples, the sensor elements 34 could be spacedcloser together or farther apart than as shown. In the shown example,there are eight rows arranged in a non-staggered orientation (i.e., onerow above another row), though in further examples, the rows 36 could bestaggered with respect to adjacent rows.

The matrix formation of the sensor array 30 further includes one or morecolumns 40 extending along a second direction (e.g., a second axis).Within the shown example, the second axis 42 extends generally linearlyalong the sensor array 30 in a direction that is substantiallytransverse to the first axis 38. For example, the second axis 42 can beperpendicular to the first axis 38. However, in further examples, thesecond axis 42 is not so limited to this transverse orientation, andcould extend at other angles with respect to the first axis 38. Ofcourse if the array 30 has a curvature, the second direction can followthe curvature.

Each of the columns 40 includes a plurality of the sensor elements 34.In the shown example, the columns 40 can each include eight sensorelements in a sequence, though the columns 40 could include as few asone or more sensor elements or greater than eight sensor elements. Thesensor elements 34 within each of the columns 40 are generallyequidistant from each other, such that the sensor elements 34 aresubstantially equally spaced from adjacent sensor elements along thelength of the sensor array 30. In further examples, the sensor elements34 could be spaced closer together or farther apart than as shown. Byspacing the sensor elements 34 apart, signal cross talk between sensorelements 34 is limited/reduced. In the shown example, there are eightcolumns arranged in a non-staggered orientation (i.e., one column nextto another column), though in further examples, the columns 40 could bestaggered with respect to adjacent columns.

The matrix formation of the sensor array 30 includes the rows 36 andcolumns 40 as shown in FIG. 2. In the shown example, there are a totalof eight rows and eight columns. As such, the sensor elements 34 in thematrix formation include an 8×8 matrix formation. It is to beappreciated that the matrix formation is not limited to the 8×8 matrixformation. In further examples, the matrix formation could be larger orsmaller than as shown, such as by including a 9×9 matrix formation (orlarger), or by including a 7×7 matrix formation (or smaller).

In further examples, the matrix formation is not limited to including anequal number of sensor elements 34 in each of the columns 40 and rows36. Rather, the matrix formation may include columns 40 and rows 36having different numbers of sensor elements 34. In some examples, thematrix formation includes an 8×6 matrix formation, a 6×8 matrixformation, or the like. In other examples, each of the rows and/or eachof the columns could have a different number of sensor elements 34 thanin adjacent rows or columns, respectively. For instance, one of the rowscould have eight sensor elements while another row has a larger orsmaller number of sensor elements. Likewise, one of the columns couldhave eight sensor elements while other columns have a larger or smallernumber of sensor elements. Accordingly, the matrix formation is notlimited to the example as shown in FIG. 2, and could include nearly anycombination of sensor elements arranged in rows 36 and columns 40. Thematrix formation is not limited to including the rectangularly shapedconfiguration of sensor elements 34. In yet another example, the matrixformation can include the sensor elements 34 arranged in an “X” typeshape, “T” type shape, or the like.

Turning now to FIG. 3, the sensor elements 34 will be described in moredetail. It is to be appreciated that while FIG. 3 depicts only onesensor element 34, the remaining, unshown sensor elements 34 may besimilar or identical in shape, structure, and function as the sensorelement 34 shown in FIG. 3. Moreover, the sensor element 34 is not shownin attachment with the supporting material 32 for illustrative purposesand to more clearly depict portions of the sensor element 34. However,in operation, the sensor elements 34 will be supported by (e.g.,attached to) the supporting material 32.

Each sensor element 34 further includes a transmitter 52. Thetransmitter 52 is supported (e.g., fixed) to the supporting material 32and spaced a distance away from the outer surface 18 of the test object12. The transmitter 52 can transmit one or more signals 53, such asenergy, pulses, and/or other impulses, into the test object 12. As isgenerally known, the transmitter 52 can be controlled such that thesignal 53 has various timings, durations, shapes, etc. Similarly, thesignal 53 includes any number of frequencies, depending on the materialof the test object 12. It is to be appreciated that the signal 53 issomewhat generically depicted in FIG. 3 as a straight line. Inoperation, the signal 53 need not travel along a linear path, and couldinclude bends or the like as a result of being transmitted into the testobject 12.

Each sensor element 34 further includes a receiver 54 attached to thesupporting material 32. The receiver 54 is supported (e.g., fixed) tothe supporting material 32 and spaced a distance away from the outersurface 18 of the test object 12. The receiver 54 can receive thereflected signals 53 from the transmitter 52. In particular, thereceivers 54 of each of the sensor elements 34 receive the signals 53after the signals 53 have reflected from within the test object 12. Thereceiver 54 is spaced a distance away from the transmitter 52. In oneexample, to further improve transmission and reception of the signal 53,the receiver 54 is separated from the transmitter 52 by an acousticbarrier 56. The acoustic barrier 56 is somewhat generically depicted, asit is to be understood that the acoustic barrier 56 can comprise anumber of different structures. In one example, the acoustic barrier 56includes a cork material or the like, though any number of structuresand materials are envisioned.

The signal 53 is used to detect a characteristic 60 of the test object12. In the shown example of FIG. 3, the characteristic 60 includescorrosion in the test object 12. However, the characteristic 60 is notlimited to including corrosion, and may further include imperfections(flaws, cracks, voids, inclusions, etc.), dimensions (wall thickness,length, etc.), or the like. Indeed, the characteristic 60 is somewhatgenerically depicted in FIG. 3 as it is to be appreciated that thecharacteristic 60 represents any number of items to be detected.Further, while the characteristic 60 is shown to be positioned at a wallof the test object 12 (e.g., an inner wall), the characteristic 60 couldbe positioned entirely within the walls of the test object 12.

In operation, the sensor elements 34 detect both the presence/absence ofthe characteristic 60 (e.g., corrosion, etc.), and can map the locationof the characteristic 60 in the test object 12. For example, thetransmitter 52 transmits the signal 53 into the test object 12. Thesignal 53 passes from the transmitter 52 and at least partially into thetest object 12 (signal 53 represented in dashed-line form within thetest object 12). The signal 53 may at least partially reflect fromwithin the test object 12. In the shown example, the signal 53 canreflect from the characteristic 60 of the test object 12. The signal 53may completely reflect off the characteristic 60 or, in other examples,may only partially reflect off the characteristic 60. The portion of thesignal 53 that is reflected off the characteristic 60 is received withthe receiver 54. Based on the reception of the signal 53 by the receiver54, the ultrasonic sensor assembly 10 can detect the presence/absenceand location of the characteristic 60 on the curved wall. In particular,information pertaining to the signal 53 received by the receiver 54 issent to the controller 20. As is generally known, the controller 20 cananalyze the signal 53 to determine the presence/absence and location ofthe characteristic 60.

Turning now to FIG. 4, the ultrasonic sensor assembly 10 is shown in theprocess of mapping the characteristics 60 (e.g., corrosion) of the testobject 12. In particular, the sensor array 30 is positioned in proximityto the outer surface 18 of the test object 12. The sensor array 30 isthen moved with respect to the test object 12. The sensor array 30 canbe moved in a variety of directions. For example, the sensor array 30can be moved in a first direction 80 that extends along a length of thetest object 12. Similarly, the sensor array 30 could be moved in asecond direction 82 that is substantially transverse to the length ofthe test object 12. In further examples, the sensor array 30 is notlimited to being moved in the first direction 80 or the second direction82, and instead could be moved at an angle (e.g., 45° angle, etc.) withrespect to the first direction 80 and second direction 82.

As the sensor array 30 is moved along the test object 12, thetransmitters 52 of each of the sensor elements 34 in the sensor array 30are triggered to transmit the signals 53. In one example, thetransmitters 52 of all of the sensor elements 34 are triggered totransmit the signals 53 simultaneously. In another example, thetransmitters 52 of the sensor elements 34 are not triggeredsimultaneously, and instead, may be triggered separately, such as bytriggering only a portion of the transmitters 52 followed by anotherportion of the transmitters 52 to transmit the signals 53. Indeed, it isto be appreciated that the transmitters 52 of the sensor elements 34 canbe triggered to transmit the signals 53 in any number of combinations(e.g., simultaneously or non-simultaneously). The receivers 54 of eachof the sensor elements 34 will receive the respective signal sent fromthat transmitter 52 of the same sensor element 34.

The sensor elements 34 can be used to detect and map the location of thecharacteristics 60 in the test object 12. For example, the controller 20may include an electronic representation of the test object 12, such asa two-dimensional or three-dimensional representation of the test object12. As is generally known, the controller 20, in operative associationwith the sensor array 30, can correlate the location of the sensor array30 respective to the test object 12 with the electronic representationof the test object 12. The controller 20 tracks the sensor array 30 asthe sensor array 30 moves along the outer surface 18 of the test object12, such as in the first direction 80 and/or second direction (or otherdirections). The sensor array 30 can detect the characteristics 60 ofthe test object 12 as the sensor array 30 is moved along the test object12 and convey this information to the controller 20. Thesecharacteristics 60 are then mapped and stored by the controller 20 withrespect to the electronic representation of the test object 12.Accordingly, the controller 20 can map and plot the characteristics 60of the test object 12 (as detected by the sensor array 30) on theelectronic representation as the sensor array 30 is moved along the testobject 12.

By providing the ultrasonic sensor assembly 10 with the sensor array 30,the test object 12 can be more quickly and accurately analyzed. Inparticular, the sensor array 30 will detect the characteristics 60 ofthe test object 12 and map these characteristics on the electronicrepresentation of the test object 12. The sensor array 30 has a largerarea, thus allowing for a larger detection range of the test object 12at one location. Further, providing the plurality of sensor elements 34in the sensor array 30 gives more accurate detection and mapping of thecharacteristics 60.

The invention has been described with reference to the exampleembodiments described above. Modifications and alterations will occur toothers upon a reading and understanding of this specification. Exampleembodiments incorporating one or more aspects of the invention areintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims.

What is claimed is:
 1. An ultrasonic sensor assembly for testing atubular pipe having a cylindrical shape and having an elongation alongthe extent of the pipe, the ultrasonic sensor assembly comprising: aflexible supporting material having flexibility configured for allowingbending of the supporting material to conform to the cylindrical shapeof the pipe; and a plurality of operable sensor elements arranged in amatrix formation upon the flexible supporting material, the matrixformation comprising a plurality of rows of the sensor elements and aplurality of columns of the sensor elements; wherein the flexiblesupporting material being configured for placement of the columns of thematrix formation to extend along the elongation of the pipe and theflexible supporting material being configured for placement of the rowsof the matrix formation to extend transverse to the elongation of thepipe, with the flexible support material being configured to flex forpositioning the sensor elements within each row in a respective arc thatfollows a curve of the cylinder shape of the pipe.
 2. The ultrasonicsensor assembly of claim 1, wherein the supporting material isconfigured to be a resilient member.
 3. The ultrasonic sensor assemblyof claim 1, wherein the supporting material includes a polyimidematerial.
 4. The ultrasonic sensor assembly of claim 1, wherein thesupporting material includes an engineering plastic.
 5. The ultrasonicsensor assembly of claim 1, wherein for each sensor element the sensorelement includes a transmitter and a receiver.
 6. The ultrasonic sensorassembly of claim 5, wherein the test object has an outer surface and,for each sensor element, the flexible supporting material and thetransmitter are configured such that the transmitter is supported by theflexible supporting material at a spaced distance away from the outersurface of the test object.
 7. The ultrasonic sensor assembly of claim5, wherein the test object has an outer surface and, for each sensorelement, the flexible supporting material and the receiver areconfigured such that the receiver is supported by the flexiblesupporting material at a spaced distance away from the outer surface ofthe test object.
 8. The ultrasonic sensor assembly of claim 1, whereinthe sensor elements are configured to map a location of a characteristicin the pipe.
 9. A method for testing a tubular pipe having a cylindricalshape and having an elongation along the extent of the pipe using anultrasonic sensor assembly, the method comprising: providing theultrasonic sensor assembly comprising: a flexible supporting materialhaving flexibility configured for allowing bending of the supportingmaterial to conform to the cylindrical shape of the pipe; and aplurality of operable sensor elements arranged in a matrix formationupon the flexible supporting material, the matrix formation comprising aplurality of rows of the sensor elements and a plurality of columns ofthe sensor elements, wherein the flexible supporting material beingconfigured for placement of the columns of the matrix formation toextend along the elongation of the pipe and the flexible supportingmaterial being configured for placement of the rows of the matrixformation to extend transverse to the elongation of the pipe, with theflexible support material being configured to flex for positioning thesensor elements within each row in a respective arc that follows a curveof the cylinder shape of the pipe; placing the ultrasonic sensorassembly onto the pipe comprising: engaging the flexible supportingmaterial to the pipe to place the columns of the matrix formationextending along the elongation of the pipe and the rows of the matrixformation extending transverse to the elongation of the pipe; andbending the flexible support material for positioning the sensorelements within each row in a respective arc that follows a curve of thecylinder shape of the pipe; and operating the sensor elements.
 10. Themethod of claim 9, wherein the step of providing the ultrasonic sensorassembly includes providing the assembly such that the supportingmaterial is configured to be a resilient member.
 11. The method of claim9, wherein the step of providing the ultrasonic sensor assembly includesproviding the assembly such that the supporting material includes apolyimide material.
 12. The method of claim 9, wherein the step ofproviding the ultrasonic sensor assembly includes providing the assemblysuch that the supporting material includes an engineering plastic. 13.The method of claim 9, wherein the step of providing the ultrasonicsensor assembly includes providing the assembly such that each sensorelement the sensor element includes a transmitter and a receiver. 14.The method of claim 13, wherein the test object has an outer surfaceand, and the step of providing the ultrasonic sensor assembly includesproviding the assembly such that for each sensor element, the flexiblesupporting material and the transmitter are configured such that thetransmitter is supported by the flexible supporting material at a spaceddistance away from the outer surface of the test object.
 15. The methodof claim 13, wherein the test object has an outer surface and, and thestep of providing the ultrasonic sensor assembly includes providing theassembly such that for each sensor element, the flexible supportingmaterial and the receiver are configured such that the receiver issupported by the flexible supporting material at a spaced distance awayfrom the outer surface of the test object.
 16. The method of claim 9,wherein the step of providing the ultrasonic sensor assembly includesproviding the assembly such that the sensor elements are configured tomap a location of a characteristic in the pipe.